A tunable laser (TL) is a laser that can continuously change, in a particular range, a laser beam output wavelength. The tunable laser is mainly applied to coherent modulation optical transmission, and the coherent modulation optical transmission has become a mainstream solution for long-distance optical transmission at a rate of 100 G or higher. As technologies advance, a requirement for the tunable laser becomes higher. A tunable semiconductor laser based on a semiconductor technology has advantages of a small volume, high integration, and the like. The tunable semiconductor laser is a mainstream product in the tunable laser field.
In the prior art, a reflectivity of a reflector of a tunable semiconductor laser is adjustable. The reflectivity of the reflector may be changed by adjusting a driving condition of the reflector, and the driving condition of the reflector is fixedly set based on a target wavelength. However, as a service time or an operating environment changes, a relationship between the driving condition of the reflector and the reflectivity of the reflector may change, thereby resulting in performance deterioration of the tunable laser.